Previously, in order to obtain a specific amount of DNA, the DNA was subjected to a polymerase chain reaction (PCR), which involved repeating a number of steps. In a PCR the temperature of a test piece is increased to 95° C. for breaking the hydrogen bond of double DNA chains;                the temperature of the test piece is decreased to 45° C. for binding with a primer in order to reproduce the DNA; and        the temperature of the test piece is increased to 74° C. to reproduce DNA by extending the primer using heat-resistant polymerase.        
In such a DNA amplifying reaction, a test piece with reaction solution is contained in a tube-shaped plastic reaction container. The container is generally placed into an aluminum block, and the above-noted heat cycles are repeated.
However, because the reaction solution is repeatedly heated and cooled, a long time is required to obtain a specific amount of DNA. In addition, the thermal accuracy for controlling the temperature of the reaction solution is low, so that DNA other than the target DNA may be reproduced.
To resolve the above drawbacks, the present invention provides a solid-state substrate for easily immobilizing DNA and reproducing DNA in accordance with a DNA amplifying reaction, as well as chips having DNA immobilized thereon, and a method for amplifying DNA.